1. Field of the Invention
This invention relates in general to computer systems, and more specifically to a universal retention apparatus for a circuit board.
2. Description of the Related Art
Personal computer systems have attained widespread use. A personal computer system can usually be defined as a desktop or portable microcomputer that includes a system unit having a system processor or central processing unit (CPU) with associated memory, a display panel, a keyboard, a hard disk storage device or other type of storage media such as a floppy disk drive or a compact disk read only memory (CD ROM) drive. These personal computer systems are information handling systems that are designed primarily to give independent computing power to a single user or group of users and are inexpensively priced for purchase by individuals or small businesses.
Efficiency is desirable for computer systems that are expandable/upgradable. In such expandable and upgradable personal computer systems, the so-called "motherboard" or system planar of the computer is designed for add-on boards or daughter cards, for example, processors or memory circuit board cards that can be easily exchanged or upgraded. Typically, modern computer systems have such processors and memory circuit board cards located in a cartridge installed directly on the motherboard or another circuit board and held in place by a retention apparatus.
There are several important considerations for a retention apparatus. The retention apparatus must permit the daughter card to connect to a connector coupled to the main circuit board. Further, the retention apparatus must hold the daughter card in a connected position orthogonal to the circuit board with the connector. The design of the apparatus dictates the size and style of cartridges capable of installation. A retention apparatus that enables a computer system to install different types of cartridges is desirable in terms of efficiency and upgradability. An efficient retention apparatus enables a manufacturer to package microprocessors using single-edge technology. Single-edge technology allows microprocessors to be mounted onto single-edge processor cards, which can then be inserted into single edge connectors. The single-edge connector is mounted on a circuit board.
Another consideration for a retention apparatus is whether the apparatus can support a heatsink coupled to the daughter card. Heatsinks are becoming more and more necessary due to advances in microprocessor technology. Such advances have increased both the operating speed and the heat produced by microprocessors. Therefore, processor circuit board cards generate more heat than earlier processors. Typically, a separate retention apparatus for supporting only a heatsink is coupled to a main circuit board in position close to a heat generating daughter card.
There are a number of processor cartridges available for computer systems including the Single Edge Contact (SEC) processor cartridge and the Single Edge Processor Package (SEPP). Both types of processors are single edge, for example, "PENTIUM II.TM." and "CELERON.TM." each have a single-edge contact. However, the designs of an SEC and an SEPP are not compatible. The SEPP has a heatsink thermal plate coupled to the circuit board for the processor. Currently, different retention systems are used depending on the type of computer system assembled. Assembly errors occur when the type of retention apparatus placed on circuit board does not match the processor to be installed later in the manufacturing process. Moreover, a customer purchasing a system with a retention apparatus for only one type of single edge processor cannot alter the computer system without also altering the type of retention apparatus, thereby increasing the cost of any upgrade.
What is needed is a universal retention apparatus that is capable of attaching more than one type of single-edge processor card. Further, a universal retention apparatus is needed that can support a heat sink as well as a processor card.